適用于：要求隨負載的性質逐級調速的各種傳動機械如機床、礦山、冶金、紡織、印染、化工等行業。Applications:widelyusedinsuchindustrywhichhavestepchangesofrotationalspeedtomeettherequirementsofloadcharacter,asmachinetools,mining,metallurgy,textile,printinganddyeing,chemicalindustryandagriculturalmachinery,etc.特點：采用改變繞組的接法來變換電機的轉速和輸出功率，使其與機械設備的負載特性相匹配，簡化了變速系統，高效、節能。Features:simplifyspeed-changingsystemsbychangingtheconnectiontoobtaindifferentoutputandspeed.變速方案：雙速、三速、四速Pole-changingmode:double,threeorfourspeed